Accumulators



Oct. 2, 1956 T. J. M CUISTION ACCUMULATORS Filed Oct. 22, 1953 mwzzvrox.76mm J/Vc 60/5770 BY I United States Patent ACCUMULATORS Tommy J.McCuistion, Euclid, Ohio Application October 22, 1953, Serial No.387,652

2 Claims. (Cl. 138-31) The present invention relates to the art ofaccumulators of the piston type.

As stated in my co-pending applications, it is well known that in theuse of a piston type of accumulator in connection with hydraulicequipment, as for instance in an airplane, the piercing of the wall ofthe storage chamber for the liquid might cause suflicient internaldisplacement and instantaneous increase in internal pressure to producean explosion-like bursting of the accumulator walls and a consequentscattering of the metal particles. This of course may prove very seriousand hence this type of accumulator is a real hazard under suchconditions. This old type of accumulator is objectionable also becauseof the transmission of vibrations or surging due to the operation of thepump connected to the same. These are the conditions which my presentimproved form of device is intended to correct.

Accordingly, one object of my present invention is to devise a pistontype of accumulator with means for quickly absorbing the increasedinternal pressure due to the displacement of a bullet or other objectpiercing the wall and entering the liquid-storage chamber of theaccumulator.

Another object is to devise an accumulator of this type that is capableof absorbing minor fluctuations or surges of internal pressure thatmight be due to impulses of the pump or other hydraulic mechanismassociated therewith.

Another object is to devise an accumulator of this type in which thepiston itself is provided with an auxiliary chamber within which thereis located a flexible diaphragm and which is provided with means ofcommunication through the walls of the auxiliary chamber so that thediaphragm may respond to the force of the pressure.

Other objects will appear from the following description and claims whenconsidered together with the accompanying drawing.

Fig. 1 is a longitudinal sectional view of one form of my inventionembodied in a piston type of accumulator;

Fig. 2 is a longitudinal sectional view of another form of my inventionembodied in a piston type of accumulator; and

Fig. 3 is a longitudinal sectional view of still another form of myinvention embodied in a piston type of accumulator.

Referring now to Fig. 1 of the present drawing in detail, the metalcylinder 1 has the piston 2 which divides the interior space into anoil-containing chamber 3 and a chamber for a gaseous body, as indicatedby reference numeral 4. The end head 5 for the chamber 3 has a nozzleform of connection 6 and the passage therethrough is divided into aplurality of annularly spaced inwardly diverging passages 7 opening intothe oil-containing chamber 3. With this arrangement of passages, theforce of pressure within the oil-containing chamber 3 will be divertedangularly outwardly and thus the screw-thread connection 6a will berelieved of the force of any such excessive pressure that mightotherwise disrupt such 2,764,997 Patented Oct. 2, 1956 screw-threadconnection to the nozzle 6. This nozzle has the screw-threaded plugclosure 6'.

The end head 8 for the chamber 4 may be provided with any suitable formof valve so as to permit supply of the gaseous body thereinto and toprevent escape of the same therefrom except when desired. In the presentcase I have indicated the head 8 as having an annular shoulder at theinner end of the nozzle 10 which in turn is adapted to receive theapertured screw-threaded plug 11 for engagement at its inner end withthe closure disk 12.

Disk 12 serves as an abutment for the coil spring 13 which is adapted tohold the apertured disk 14 against shoulder 9. With these parts in theposition indicated in Fig. 1, there can be no escape of the gaseous bodyfrom the chamber 4; but by forcing inwardly disk 12, to which access maybe had through the plug 11, the gaseous pressure may be relieved throughthe apertured disk 14 and around the open disk 12. The gaseous body maybe supplied to chamber 4 through nozzle 11 and its valve, justdescribed, as the disk 12 will yield to such pressure and will beautomatically closed by its spring 13 upon discontinuance of suchgaseous pressure inwardly through the nozzle 11.

The piston 2 may have suitable sealing means, as for instance multiple 0rings of elastic composition, arranged within grooves in the perimeterof the piston and with relief ports to prevent pressure lock betweenthese rings, as illustrated; and there may be the same provision in eachof the other two forms of device illustrated in Figs. 2 and 3 hereof.

In Fig. 1 of the present drawing the piston may be recognized as havingan integrally formed transverse wall 15 which is located substantiallymidway of the length of the piston; and at the side of the pistontowards the oilcontaining chamber 3 there is a screw-threaded flangedwall member 16 with a central aperture 16a of less diameter than thecentral full portion 5a between the inner ends of the diverging passages7 in the end head 5 for a purpose to be explained. The edge of the wall16 about the aperture 16a adjacent the diaphragm may be rounded so as toavoid any danger of cutting the diaphragm 17 and, for the same reason,the disk 16 and the wall 15 may be rounded in the region thereof that isadjacent the diaphragm 17. The wall member 16 is adapted to engage theouter marginal portion of the flexible diaphragm 17 so as to hold thesame in proper assembly within the annular groove provided in the wall15. The edge por- 'tion of the diaphragm may be of enlarged crosssection and may have snug engagement within its groove; and the centralportion of the wall, adjacent the diaphragm, may be cupped out so as toprovide suitable clearance which may be recognized as an auxiliarychamber between the main portion of the diaphragm and the wall 15 andthereby permit action of the diaphragm in response to any surge ofpressure within the oil-containing chamber 3.

The wall 15 is provided with a central aperture therethrough toaccommodate a tubular valve body 18 which has a closed mushroom-like end18d normally held towards the diaphragm by the coil spring 18b whichsurrounds the valve body 18 and has engagement at its two ends againstthe end 18d and the shoulder surrounding the aperture in the wall 15.The hollow valve body 18 is provided with radially disposed apertures18c therethrough which are normally in open communication with the spacebetween the diaphragm and the wall 15; and the mushroom-like end 18d isadapted to seat within the recess in the adjacent side of the wall 15when there is exerted sufficient pressure upon the diaphragm 17 from theliquid-containing chamber 3, at which time the ports 18c will be closed.The other end of the valve body 18 may have an vannular flange 18apeened over so as to maintain the same in assembly; and this side of thepiston is cupped out sufiiciently so that the valve 18 will not protrudetherebeyond.

Thus the space between the diaphragm 17 and the wall 15. may berecognized as an auxiliary chamber for the gaseous body since it isnormally in communication with the chamber 4 in Fig. I; and, in theevent of excessiye pressure within the oil-storage chamber 3, thediaphragm may first respond by movement towards the right, as viewed inFig. l of the drawing, so as to force the gaseous body from thisauxiliary chamber through the restricted passage in the valve 18 andinto the chamber 4 until the valve 18 is closed thereby. Then, uponcontinuation of such excessive pressure within the oil-storage chamber3, the entire piston may respond thereto by moving bodily towards theright, as viewed in Fig. I of the drawing, and thereby effecting acorresponding compression of the gaseous body within the chamber 4. Uponrelief of such excessive pressure within the chamber 3, the parts willbe returned automatically to their positions as indicated in Fig. 1,which is to be recognized as normal.

In the form of device illustrated in Fig. 2, the oilstorage chamber 3*may have a conventional supply connection 6' in the screw-threaded endhead 5, a closure plug 65 in the screw-threaded opening 6a; and thechamber 4' for the gaseous body may have the same form of valve in theend head thereof as in Fig. 1 or any other conventional form of suchvalve, and there may be the same provisions for the corresponding endheads of the chambers in the form of device illustrated in Fig. 3thereof.

Referring further to the form of accumulator shown in Fig. 2 of thedrawing, the piston has a transverse wall 21 substantially midway of thelength thereof and this wall 21 has an annular groove to receive andsnugly hold the enlarged marginal portion of the flexible diaphragm 22upon the side of the piston that faces the liquid-storage chamber 3'.The diaphragm is held in such asembly by means of the screw-threadedflanged disk 23. The disk 23 and wall 21 are rounded in the region ofthe diaphragm 22 for the same reason as explained in connection with theform of device shown in Fig. 1 of the present drawing. The disk 23 isprovided with a central aperture 23a of outwardly converging or taperingform that is adapted to receive inseating engagement the correspondinglyformed valve- 24 which is mounted upon the central portion of thediaphragm 22. The valve member 24 has a centrally disposed shank whosefree end is swaged over so as to hold in engagement against the oppositeside of the diaphragm the valve disk member 25 which may have seatingengagement with the shoulder about the centrally disposed port 21a inthe wall 21 of the piston. The space between the diaphragm 22 and thewall 21 may beregarded as an auxiliary chamber. The coil spring 26normally forces the valve 24 to closed position upon its seat in theopening 23a; and, at the same time, the valve 25 is held off of itsseat. In this condition it is assumed that there is no excess pressurewithin the chamber 3'. In the event, however, of such excess pressurewithin the oilcontaining chamber, the valve 24 may first be forced openso as to permit exertion of pressure by the diaphragm upon the gaseousbody within the auxiliary chamber within the piston and within the mainchamber 4' through the comparatively restricted aperture 21a; and, uponcontinuance of such excess pressure, the valve 25 may be forced toclosed position and the piston may then be moved bodily towards theright, as viewed in Fig. 2 of the present drawing, so as to exert stillfurther compression of the gaseous body within the chamber 4'. Uponrelief of such excess pressure, the parts will return automatically tothe position indicated in Fig. 2 which may be recognized as normal.

In the form of accumulator illustrated in Fig. 3 of the accompanyingdrawing, the piston 30 is provided with a transversely extending wall 31substantially midway of the length thereof and this wall is providedwith a central opening 311: therethrough that is covered by a body 32 ofporous material as for instance porous metal seated upon the side of thewall 31 that is adjacent the oil-storage chamber 3". The flexiblediaphragm 33 has an enlarged outer edge snugly engaged within a groovein the wall 31 and is held in such assembly by the slip ring 34 whichengages the same and which is held in such engagement by the disk ofporous metal 35 or other suitable porous material. The ring 34 isrounded in the region of the diaphragm 33 in order to preclude anydamage thereto. As indicated in Fig. 3 of the present drawing, there issubstantial space between the diaphragm 33 and the porous disks 32 and35 so as to provide what might be recognized as an auxiliary chamberwithin the piston 30. Upon initial exertion of excess pressure withinthe oil-storage chamber 3", such pressure may be transmitted through theporous disk 35 and exerted upon the diaphragm 33 which will respondthereto by transmitting such pressure to the auxiliary chamber betweenthe same and the porous disk 32. Continuation of such excess pressuremay cause the same to be transmitted through the porous disk 32 into thechamber 4". Thus there may first be response to such excess pressure byand entirely within the relatively confined auxiliary chamber upon theopposite sides of the diaphragm 33 and then, if need be, within thechamber 4 in the manner explained. The condition of the diaphragm 33, asindicated in Fig. 3 of the accompanying drawing, is to be recognized asnormal.

This invention in each of the several forms herein illustrated,includes. a unitary assembly of piston and diaphragm that is responsivebodily to the excess pressure Within the liquid-containing chamber; andthere is also provided in each instance between the diaphragm and thepiston an auxiliary chamber that is responsive to the initial exertionof such excess pressure, together with pressure-responsive means. forpermitting transmission of such excess pressure to the chamber for thegaseous body. Each of these several forms of device is of simple andcompact construction and is capable of operation in an eflicient anddependable manner. in the prevention of the damage that might occur inthe event of excess pressure within the liquid-storage chamber, as aboveexplained.

It is to be understood that the present forms of disclosure are merelyfor the purpose of illustration and that there might be still furthermodifications without departing from the spirit of my invention asherein set forth and claimed.

What I claim is:

1. An accumulator comprising a cylinder, a piston reciprocatabl'e'longitudinally within said cylinder and dividing the interior thereofinto separate chambers for a liquid and a gaseous body, respectively,said chambers having inlet and outlet openings through the wall of saidcylinder for passing the liquid and gaseous body, respectively, saidpiston having transversely disposed fluid-transmitting end walls spacedfrom each other to a substantial extent lengthwise of the cylinder, atflexible diaphragm extending transversely and substantially midwaybetween the end walls of said piston and having its marginal portionsecured between and in spaced relation to said end walls so as to beresponsive to pressures within said chambers, and valve means providedupon said diaphragm for controlling the flow of the liquid and thegaseous body through the end walls of said piston.

2. An accumulator comprising a cylinder, a piston reciprocatablelongitudinally within said cylinder and dividing the interior thereofinto separate chambers for a liquid and a gaseous: body, respectively,said chambers having inlet and outlet openings through the wall of saidcylinder for passing the liquid and gaseous body, respectively, saidpiston having transversely disposed fluid-transmitting end walls spacedfrom each other to a substantial extent lengthwise of the cylinder, aflexible diaphragm extending transversely and substantially midwaybetween the end walls of said piston and having its marginal portionsecured between and in spaced relation to said end walls so as to beresponsive to pressures within said chambers, and a one-way valveprovided upon said diaphragm for each of said transversely disposedwalls for controlling flow of the liquid and gaseous body, respectively,therethrough, whereby each of said valves is adapted to be closed bypressure upon the opposite side of said diaphragm.

References Cited in the file of this patent UNITED STATES PATENTSKremiller Mar. 11, 1947 Snyder Apr. 15, 1952 Snyder Dec. 22, 1953McCuistion Nov. 23, 1954

